6h30 dac output circuit wanted..anyone?

[fdegrove]

Hi,

Perugini made this design

Jaap,

Can you tell us more about this circuit?
Where you found it and what it was designed for etc.,please?

Tone,

There is little point for you to start building anything at this stage yet.

All,

Is a de-emphasis always used on DACs?
I can't recall having seen one on the Sheldon Stokes design...if one is used,is it always the same passive circuit?

Obviously I am no Digital Wizzkid,

[reinhard]

Hello,

the pot in the Perugini circuit is not a volume control, the resistance is used to make the Current Voltage conversion.

Reinhard

[tone]

hi all,
work out the pcb today..four different file, attach it together...Messy!!

>Receiver/digital coupler/kusunoki Asy-clock/Dac.
signal hard-wire with silver wire..output stage not yet..

[tone]

not according to scale ofcourse..

tone

[Jaap]

is indeed the analog stage after the dac chip and it uses the 6H30. This was the question.
The pot at the front is for the i/v conversion. After you have tried it for the right resistance you can exchange it for a normal resistor.
I have tried this design and it has a very neutral character, I had no complains, it works fine.

Jaap

[Joel]

Originally posted by reinhard
...the pot in the Perugini circuit is not a volume control, the resistance is used to make the Current Voltage conversion.

Reinhard, can you explain that? I don't know what you mean by "current voltage conversion".

[fdegrove]

Hi,

Joel,

For a DAC to work properly you need to convert current to voltage.

A shunt resistor is one of the possible methods.

I am no digital expert but if you care to dip into the "Digital" section you'll find miles of "bones" to chew on.

Cheers,

[Brett]

Originally posted by Joel
I don't know what you mean by "current voltage conversion".

Joel, some DACs output a <i>current</i> that's proportional to the digital input. The TDA1541, PCM63 and a number of others are current output, whereas many others are voltage out. These Vout models use feedback around an opamp to do the I to V conversion, with the opamp being built onto the chip substrate.

In this case the pot, or a resistor will generate a voltage from the current output of the DAC, which is then amplified to a suitable level. Iout DACs put out less than 2mA for 0dBFSD.

HTH

[filippo22]

On my site you can find a dac tube output circuit using a pair of E182CC, these tube is the same as the 6H30 (russian code) an can be also substitute with the ECC99


ciao
Filippo
www.audiofanatic.it

[tone]

rgds
tone